The primary prime member can add up to 3 other accounts, but those accounts cannot access prime instant streaming. This is the one thing I really dislike, besides the lack of an android app. I have to use my wife's login for streaming, but that also means I have full access to her account and history. That is mostly fine - we have no secrets - but we have a friend that left Amazon logged in so her kids could stream, then later found her youngest loaded a bunch of DVDs and such into the shopping cart. Its not great around Christmas time either, if you want to keep gifts secret. We use roku players, and simply don't let the kids steam on the computers.